The present invention relates to a method of medical treatment using a radioactive isotope (RI), and more particularly to a production method and an injection device for using an RI having a short half life as an injection fluid.
With respect to a conventional system, the .sup.15 O series has been introduced into a living body as an RI gas through an inhalation method. In this case, since the RI gas is inhaled through a mask, the RI gas can leak from the mask, so that the background and stability of a positron emission tomography (PET) apparatus may be impaired. In addition, with respect to the living body, since the RI gas is absorbed into blood vessels through the lungs, the period of inhalation becomes long, with the result that exposure.
Furthermore, since the aforementioned .sup.15 O series RI gases have short half lives of only two minutes or thereabouts, in order to be taken in as a gas through the lungs as describe above, it is necessary to use a large amount of RI gas, thus increasing the operator's exposure.
In addition, in a case where an H.sub.2.sup.15 O gas is used as an injection fluid, a .sup.15 O.sub.2 gas is heated by using platinum or palladium as a catalyst, and an H.sub.2 gas is also made to pass through the catalyst when the .sup.15 O.sub.2 gas passes through the catalyst, so as to synthesize H.sub.2.sup.15 O. Then, a caponized compound is subjected to bubbling in physiological saline so as to produce an injection drug. However, since the half life is short, the efficiency has been poor.